Powder-Tight Packaging

ABSTRACT

The invention relates to a powder-tight packaging for a good, particularly a powdery good, which has an inner frame and is formed from at least one folding blank that comprises at least one rear side ( 2 ), one front side ( 1 ) and two lateral sides ( 3, 4 ) of the packaging, these sides being attached to one another while being delimited by fold lines. In order to construct the packaging, the folding blank is closed to form tubular shape. The folding blank also has at least one top tab ( 8 ) and at least one bottom tab ( 9 ). The inventive packaging is characterized in that the bottom surface and the top surface of the packaging are each provided with a quadrilateral, particularly rectangular shape, and the folding blank has additional lateral areas ( 6 ) that are arranged in such a manner that, in the closed tubular shape, one of the additional lateral areas extends between the rear side and each lateral side and between the front side and each lateral side so that the closed tubular shape has, in its middle area, a cross-section with more than four sides, preferably with eight sides.

The invention relates to a powder-tight packaging for a product, in particular for a pulverulent product, preferably a washing or cleaning powder, which packaging is formed from a folding blank which comprises at least one rear face, one front face and two end faces of the packaging that are attached to one another and delimited by folding lines, which, in order to construct the packaging, is closed to form a tubular shape and which comprises at least one lid flap and at least one base flap for closing the base and the lid and for forming the base surface and the lid surface of the packaging, which surfaces respectively adjoin lower and upper edges of the front face, the rear face and/or the end faces via folding lines.

The invention also relates to a folding blank for the abovementioned packaging.

Packagings of this type have been commercially available for decades in a cuboidal form, in particular for detergent powders. Packagings of this type are also used for pourable food products, such as breadcrumbs, cornflakes or the like.

A packaging of this type is to be distinguished particularly from packagings which are formed from a so-called “wrap-around blank” which is used particularly for bulky products, for example for detergent tablets. In this case, the tablets to be packed are stacked, for example, on a base region of a folding blank and the blank is then folded up and wrapped around the product in order to close the packaging and to surround the bulky item, and the packaging is closed. A packaging of this type does not particularly have to be powder-tight.

In contrast, in the packaging of the generic type, a packaging space is first formed which remains open on only one side and then is filled with the

pourable product, after which the last side, and therefore the entire packaging, is closed. To this end, a tubular shape may initially be formed from the blank and the base may then be closed. Filling would then be carried out and finally the lid would be closed. In principle, however, it is also possible to lastly close, for example, one end face after the filling operation.

The invention is based on the object of improving handling of a packaging of the generic type mentioned in the introduction.

According to the invention, this object is achieved in that the base surface and the lid surface of the packaging are each of quadrilateral, in particular rectangular, design and the folding blank comprises additional side regions which are arranged in such a way that, in the closed tubular shape, one of the additional side regions in each case extends between the rear face and each end face and between the front face and each end face, so that the closed tubular shape has a cross section with more than four corners, preferably eight corners, in its middle region, and in that each of the additional regions tapers to form a point at its lower and upper ends, with the lower point being involved in the formation of one of the corners of the base surface and the upper point being involved in the formation of one of the corners of the lid surface.

As a result, the packaging according to the invention is advantageously given a shape in which the lid and the base remain rectangular but the body of the packaging has eight surfaces. In contrast to a cuboidal shape, this preferably leads to it being possible for the end surfaces to be narrower. This in turn advantageously makes it easier to pick up the packaging according to the invention because packagings of this type, in particular for detergent or cleaning powder, are of a size which can be picked up from the shelf from the side. However, this is easier with the packaging according to the invention because, on account of its angled design, the end-face region, which now comprises an end face and two adjoining additional side regions, better matches the rounded shape of the hand which is picking it up, is narrower in the end-face region and, in particular, is more convenient to pick up because the edges are less palpable. This is particularly advantageous for women since their hands are, on average, somewhat smaller than men's hands.

Secondly, the packaging may remain rectangular in the lid region and in the base region as is customary, so that said packaging can be opened and closed in the customary manner and, in particular, the packaging according to the invention can be produced, constructed and filled largely using conventional machines.

However, the packaging according to the invention is also easier to handle in a further regard. Since said packaging has eight edges and surfaces, the packaging according to the invention can be stacked, in particular palletized, in a much more stable manner, with the size of the required standing area not being increased. If an octagonal shape, whose edge regions are smaller than those of a rectangular shape, is required to retain the same volume, it is accordingly necessary to provide a greater volume height. However, in reality, packagings of this type, in particular for reasons of filling technology, are never filled right up to the lid, with the result that it is readily possible to vary the filling level within the packaging without having to change the height of the packaging itself, that is to say its external dimensions. In this regard, it is advantageously not necessary to makes any changes in terms of storage of the packaging according to the invention either. In Germany, the filling level shall be provided in accordance with DIN 55540.

One preferred embodiment of the packaging according to the invention provides for the additional side regions to be narrowed in relation to the width of the end faces so as to form beveled surfaces. This therefore means that, in relation to a cuboidal shape, essentially actually only the edges are broken, that is to say one vertical edge is in each case replaced by two edges which are not very widely spaced apart from one another. This particularly improves handleability and stackability of the packaging according to the invention. The additional side regions are preferably at angles of up to 135° in relation to their adjacent end faces and the rear face and the front face in the closed tubular shape. Their corner regions and edge regions therefore form a relatively large obtuse angle with these adjacent faces. In contrast to the cuboidal shape of a conventional packaging and in contrast to the rectangular shape of the lid surface and the base surface, the additional side surfaces cut the vertical edges, that is to say diagonally by an angle of approximately 45°.

The folding blank is preferably adhesively bonded in a joint region in order to form the tubular shape. To this end, an adhesive flap may preferably be provided, which adhesive flap is arranged particularly at an edge of the front face or rear face which is free of an additional side region by means of a folding line. The packaging according to the invention is then, that is to say before it is filled, adhesively bonded at the side joints, preferably by an adhesive flap and an additional side region partially overlapping for adhesive bonding purposes. However, it is of course possible to provide other adhesive-bonding means, in particular in the region of the rear face. Adhesive bonding should, however, preferably be performed such that the joint interferes with handling of the packaging to the least possible extent.

Another development of the packaging according to the invention provides for a tear-open strip to be incorporated in the folding blank and to run substantially parallel to the lid. The packaging may then also be provided in a filled and sealed manner and then intentionally opened by a consumer, by said consumer tearing off the tear-open thread and thus obviously unsealing the packaging. It is also easy to grip beneath the lid, for example using fingertips or fingernails, in the region of the torn-off tear-open strip in order to open said lid. In order to facilitate the tearing-open operation, the tear-open strip is preferably delimited by material-weakening lines. A grip tab may be arranged at one end of the tear-open strip for the purpose of grasping said tear-open strip. This grip tab is preferably comfortably large enough to enable it to be grasped in a reliable and simple manner. In particular, the grip tab could be designed to be approximately the size of a thumbnail. The user then does not particularly require any distinct fine motor skills in order to grasp this grip tab. This is particularly advantageous for elderly people. It is therefore easier to visually identify the tear-open tap. In addition, an embossed or punched-out area may be provided in the grip tab in order to improve haptics.

A next development of the invention provides for a swing-action hinge region, in which the lid remains connected to the rear face, to be left by the tear-open strip. This therefore produces a hinged lid which is easy to open and close again, preferably with respect to a lid which can be lifted off entirely and, in principle, is of course also possible.

The invention also provides for the packaging to have an inner frame. This inner frame is substantially matched to the tubular shape. An inner frame of this type further improves the stability and powder-tightness of the packaging according to the invention.

One development provides for the inner frame to protrude beyond the extent of the tear-open strip in the direction of the lid and remain undamaged by the tear-open strip. This also has two advantages. Since the inner frame protrudes beyond the tear-open strip and said tear-open strip runs at a certain distance from the lid surface, the lid can be reclosed in a more reliable manner by said lid being placed virtually over the protruding part of the inner frame during the reclosing process. In order to not adversely affect the swinging operation in the process, provision may be made for the inner frame to be rounded in accordance with the pivot path of a hinged lid. Since the inner frame additionally remains unaffected by the tear-open strip, the inner frame also ensures leak-tightness in this region too. In particular, said inner frame forms a type of labyrinthine seal with the reclosed lid.

The inner frame may be a subregion of the folding blank of the entire packaging, so that the packaging according to the invention is formed virtually in two layers from a single folding blank in substantial regions. However, the folding blank may also be formed from two separate parts with their own folding blanks for an outer casing and for an inner frame. In each of these two cases, provision is preferably made for the inner frame to be adhesively bonded to the tubular shape.

Another development of the invention proposes that a snap-action latching connection may be provided in order to reclose the lid, it being possible to arrange said snap-action latching connection particularly in the region of the lid which is remote from the swing-action hinge. The swing-action hinge could preferably be arranged on the rear face of the packaging, while the reclosing operation accordingly preferably takes place in the region of the front face. However, in addition or as an alternative, it would be entirely possible to provide closing devices of this type in the side surface region too.

For transportation purposes, the packaging according to the invention preferably has a carrying handle, preferably in the region of the lid. This carrying handle could likewise be formed by additional regions of the folding blank itself. However, provision is preferably made for the ends of a strip-like carrying handle, that is to say a type of lug, to be mounted in an articulated fashion in the upper regions of the end faces. A carrying handle of this type may be formed in a material-saving, cost-effective and robust manner, for example from a plastic strip. This plastic strip may, for example, be riveted to the end faces so as to be powder-tight. It goes without saying that a wide variety of other options for forming a carrying handle of this type are feasible.

The packaging is preferably substantially produced from paperboard and/or cardboard. In this case, at least part of the packaging may be produced from corrugated board. In particular, an inner frame is preferably produced from corrugated board, with the corrugation peaks of the corrugated board preferably running vertically when the packaging is assembled, so that this corrugation additionally increases the stacking stability of the packaging. One corrugation of this corrugated paper board may, for example, have a corrugation height and/or a half-wave length of approximately 1 mm. This leads to an extremely high degree of stability on the one hand and on the other hand prevents excessive material wear, in particular of an inner frame, which is done at the cost of the internal volume of the packaging. However, it goes without saying that other corrugations with different dimensions are feasible in a variety of ways.

Within the scope of invention, it is possible for the additional side regions to be deformed, it being possible for these deformed edges to have a rolling shape, for example. According to the invention, it is also feasible for the edges to have a shape which is curved in any desired direction.

The folding box and the associated inner frame can be at least partially adhesively bonded to one another. In this case, said holding box and associated inner frame are adhesively bonded to one another at the edge in the circumferential direction in such a way that a tube which is open at the top and bottom is produced. Since these blanks have to be transported, in order to be filled, so that as much space as possible is saved, it is expedient to not transport the tube in the assembled state but rather in a folded together state. To this end, the assembled tube is bent across the straight, uninterrupted longitudinal edges and thus folded flat in known methods.

In the case of the packaging according to the present invention, this is not possible, or is possible only to a limited extent, when at least one of the vertical edges is at least partially broken. Therefore, the invention additionally provides for auxiliary folding lines to be provided which are arranged such that, when the folding box is folded together, they, as a replacement for or as a continuation of straight edges, allow the folding box to be folded together. For filling purposes, a folding box of this type is again assembled and then adhesively bonded at the base. After the filling operation is complete, the lid can also be adhesively bonded.

The auxiliary folding lines described here may be provided both on the folding box and also on the inner frame. According to the invention, it is also possible to provide these auxiliary folding lines only on one of these two elements.

According to the invention, auxiliary folding lines of this type may be provided on each desired face and in any desired orientation. For example, said auxiliary folding lines may run on the side walls in the longitudinal direction, that is to say from the edge of the base to the edge of the lid. They may also be provided centrally on the corresponding side wall.

According to the invention, the auxiliary folding lines may be arranged such that they take over the original function of the edges when the folding box is folded together in accordance with the method according to the invention. This means that the tube which is produced by the adhesive bonding operation can be folded flat across these folding lines.

In the case of a packaging of this type, it may be advantageous for said packaging to be of relockable design. To this end, connection options may be provided between the lid and the inner frame, these connection options holding said lid in its closed position after the reclosing operation.

A connection option of this type could be formed as a snap-action latching connection, with, for example, at least one latching element and at least one snap-in lug being used. According to the invention, it would be possible for the latching element to be fitted to the inner face of the lid of the folding box and for the snap-in lug to be fitted to the upper face of the inner frame.

The number, shape or design of such connection options are in no way restricted by the examples mentioned here. Instead, the present invention covers all imaginable embodiments of a connection option of this type.

In order to further facilitate the reclosing operation, it may be advantageous to match the inner frame to the closing movement of the lid. For example, the upper edges of the inner frame could be equipped with a quarter-circle-like side termination which sets and releases a pivot arc of the lid, so that it is easier to close the packaging. Further possible design options for an easier closing movement are also feasible.

The present invention is in no way restricted to the number of individual parts of the packaging, or rather the folding box and the inner frame. It may, for example for production reasons, be advantageous to produce the inner frame and the folding box integrally or from two separate blanks. In the last-mentioned embodiment, the folding box and inner frame could be at least partially adhesively bonded to one another during the production process.

The invention also relates to blanks for a packaging according to the invention and these blanks may be of both integral or else multipartite design, for example the inner frame and folding box may be formed as separate blanks.

Blanks of this type may be equipped with adhesive flaps in order to improve adhesive bonding to a tube. Overlapping regions on the walls of the folding box or the inner frame are also feasible within the scope of the present invention.

Exemplary embodiments, which disclose further inventive features but to which the scope of the invention is not restricted, are illustrated in the drawing, in which:

FIG. 1 shows a blank for a first embodiment of an outer carton of a packaging according to the invention,

FIG. 2 shows a perspective view of the packaging according to the invention which is obtained with the blank from FIG. 1,

FIG. 3 shows a side view of the packaging according to FIG. 2,

FIG. 4 shows a plan view of the packaging according to FIGS. 2 and 3,

FIG. 5 shows a view of the packaging according to FIG. 4 from beneath,

FIG. 6 shows a second exemplary embodiment of a blank for the outer carton of a packaging according to the invention,

FIG. 7 shows a perspective view of the packaging produced with the blank according to FIG. 6,

FIG. 8 shows a side view of the packaging according to FIG. 7,

FIG. 9 shows a view of the packaging according to FIG. 7 from an end,

FIG. 10 shows a plan view of the packaging according to FIG. 7, and

FIG. 11 shows a view the packaging according to FIG. 7 from beneath.

FIG. 1 shows a first exemplary embodiment of a blank for an outer carton of a packaging according to the invention. This blank comprises the front face 1, the rear face 2 and the side surfaces 3 and 4 of the packaging. These four surfaces can be folded and connected to one another to form a tubular shape, with an adhesive flap 5 being provided for connection purposes. When the tubular shape is closed, the vertical edge regions of the tubular shape are formed by additional surface regions 6, of which in each case one additional surface region 6 is arranged in the tubular shape between two of the surfaces 1 to 4 in each case. Each of these additional surface regions tapers to a point 7 at the top and at the bottom, is therefore of substantially approximately pick-like, elliptical or ship-like design.

Lid flaps 8 and base flaps 9 respectively adjoin the surfaces 1 to 4 at the bottom and at the top.

The blank according to FIG. 1 can be folded up along auxiliary folding lines 10 and in this way be stored or supplied to a packaging machine. These auxiliary folding lines 10 are necessary for this purpose since the contours of the additional surface regions 6 run rectilinearly only in one portion but are of rounded design in the vicinity of the points 7.

In addition to the blank for an outer carton, an inner frame is also preferably provided for the packaging according to the invention. This inner frame has not been illustrated in any detail in the drawing because it can be formed in a substantially similar manner to the blank according to FIG. 1, without the respective lid flaps 8 and base flaps 9. The inner frame therefore substantially has a rectangular contour. In this case, it is important with regard to the additional surface regions 6 that the inner frame has corresponding approximately congruent additional surface regions 6. This inner frame may then be folded and connected to form an inner casing tube which directly lines the outer carton and clings tightly to this outer casing or outer carton. For improved stability of the entire packaging, the inner frame and the outer carton may additionally be adhesively bonded to one another in a surface-connected or point-connected manner. The inner frame is preferably formed from corrugated board.

A packaging whose exterior is illustrated in perspective view in FIG. 2 can be formed from the blank according to FIG. 1. Identical components are identified by the same reference numerals as in FIG. 1.

FIG. 2 shows, in particular, that the lid which is formed from the lid flaps 8 and the base which is formed from the base flaps 9 are of quadrilateral, in particular rectangular, design while the central body region of the packaging has an octagonal cross section. For this purpose, the additional surface regions 6 are at angles of approximately 135° in relation to the respectively adjacent surface 1 to 4. On account of the pick-like design of the additional surface regions 6, the edges of the additional surface regions are bent and deformed. The respective points 7 are involved in forming the corners of the packaging. The packaging is easier to handle an account of the octagonal cross-sectional shape in its middle region, in particular to be grasped from the side surfaces 3 or 4.

FIG. 3 shows a front view of the packaging according to FIG. 2. FIGS. 4 and 5 respectively show a plan view of the packaging according to FIG. 2 and a view of said packaging from beneath. Identical components are again identified by the same reference numerals as in FIG. 1.

FIGS. 4 and 5, in particular, show that the surface regions 1 to 4 are of approximately convex or outwardly curved design on account of the deformation of the packaging in the additional surface regions 6. In addition, FIGS. 4 and 5, as in the blank according to FIG. 1, show that the packaging has a substantially square lid 8 and base 9 in this exemplary embodiment.

FIG. 6 shows a second exemplary embodiment of a possible blank for a packaging according to the invention. Identical components are identified by the same reference numerals as in FIG. 1.

In comparison to the blank according to FIG. 1, the additional surface regions 6 in the blank according to FIG. 6 in particular are of very pronounced design, to be precise such that virtually only rudiments of the side surfaces 2 remain, specifically an actual end surface is no longer present in the packaging produced from the blank according to FIG. 6. In the end side regions, the additional surface regions 6 directly border one another in this case, so that the packaging is acutely angled in this region. This is clear in the perspective view according to FIG. 7 which shows the packaging produced from the blank according to FIG. 6. This packaging is therefore hexagonal in its middle region, while small octagonal regions remain in the upper and lower portions.

FIG. 8 shows a front view of the packaging according to FIG. 7.

FIG. 9 shows a view of the acutely angled end face 2 of the packaging according to FIG. 7.

FIGS. 10 and 11 respectively show a plan view of the packaging according to FIG. 7 and a view of said packaging from beneath. 

1. A powder-tight packaging for a pulverulent product such as a washing or cleaning powder, comprising: at least one folding blank which comprises at least one rear face (2), one front face (1) and two end faces (3) (4) of the packaging that are attached to one another and delimited by folding lines, which folding blank, in order to construct the packaging, is closed to form a tubular shape, and wherein said folding blank further comprises at least one lid flap (8) and at least one base flap (9) for closing the base and the lid and for forming the base surface and the lid surface of the packaging, which surfaces respectively adjoin lower and upper edges of the front face (1), the rear face (2) and/or the end faces (3) (4) via folding lines, wherein the base surface and the lid surface of the packaging each have a quadrilateral shape, and wherein the folding blank comprises additional side regions (6) that extend between the rear face (2) and each end face and between the front face (1) and each end face, so that the closed tubular shape has a cross section with more than four comers in its middle region, and wherein each of the additional regions (6) tapers to form points (7) at its lower and upper ends, with the lower point being involved in the formation of one of the corners of the base surface and the upper point being involved in the formation of one of the corners of the lid surface, and wherein the packaging has an inner frame.
 2. The packaging as claimed in claim 1, wherein the closed tubular shape has an octagonal cross section in its middle region.
 3. The packaging as claimed in claim 1, wherein the additional side regions (6) are narrowed in relation to the width of the end faces so as to form beveled surfaces.
 4. The packaging as claimed in claim 1, wherein the additional side regions (6) in the closed tubular shape are situated approximately at angles of about 135° in relation to their adjacent end faces and the rear face (2) or the front face (1).
 5. The packaging as claimed in claim 1, wherein the folding blank is adhesively bonded in a joint region in order to form the tubular shape.
 6. The packaging as claimed in claim 5, wherein an adhesive flap (5) is provided for the purpose of adhesive bonding and forming the joint region.
 7. The packaging as claimed in claim 6, wherein the adhesive flap (5) is arranged at an edge of the front face (1) or rear face (2) which is free of an additional strip region by means of a folding line.
 8. The packaging as claimed in claim 1, wherein a tear-open strip is incorporated in the folding blank and runs substantially parallel to the lid.
 9. The packaging as claimed in claim 8, wherein the tear-open strip is delimited by material-weakening lines.
 10. The packaging as claimed in claim 8, wherein a grip tab is arranged at one end of the tear-open strip.
 11. The packaging as claimed in claim 10, wherein the grip tab is designed to be approximately the size of a thumbnail.
 12. The packaging as claimed in claim 8, wherein a swing-action hinge region, in which the lid remains connected to the rear face (2), is left by the tear-open strip.
 13. The packaging as claimed in claim 1, wherein the inner frame is substantially matched to the tubular shape.
 14. The packaging as claimed in claim 8, wherein the inner frame protrudes beyond the extent of the tear-open strip in the direction of the lid and remains undamaged by the tear-open strip.
 15. The packaging as claimed in claim 1, wherein the inner frame is a constituent part of the folding blank.
 16. The packaging as claimed in claim 1, wherein the inner frame is formed from a separate folding blank.
 17. The packaging as claimed in claim 1, wherein the inner frame is adhesively bonded to the tubular shape.
 18. The packaging as claimed in claim 1, wherein a snap-action latching connection is provided in order to reclose the lid.
 19. The packaging as claimed in claim 18, wherein the snap-action latching connection is arranged in the region of the side of the lid which is remote from the swing-action hinge.
 20. The packaging as claimed in claim 1, wherein a carrying handle is preferably arranged on the lid.
 21. The packaging as claimed in claim 1, wherein it is produced substantially from paperboard and/or cardboard.
 22. The packaging as claimed in claim 1, wherein at least part of the packaging is produced from corrugated board.
 23. The packaging as claimed in claim 22, wherein the inner frame is produced from corrugated board.
 24. The packaging as claimed in claim 1, wherein the additional side regions (6) are deformed in the closed tubular shape.
 25. The packaging as claimed in claim 24, wherein each deformed additional side region (6) has a rolling shape.
 26. The packaging as claimed in claim 24, wherein the deformed additional side region (6) has a curved shape.
 27. The packaging as claimed in claim 24, wherein each deformed additional side region (6) of the folding box has an elliptical or pick-like surface.
 28. The packaging as claimed in claim 1, wherein auxiliary folding lines (10) are provided on the folding box and on the inner frame.
 29. The packaging as claimed in claim 28, wherein the auxiliary folding lines (10) are provided on the side walls (3, 4).
 30. The packaging as claimed in claim 29, wherein the auxiliary folding lines (10) are provided centrally on the side walls.
 31. The packaging as claimed in claim 28, wherein, when the folding box is folded together, the auxiliary folding lines (10) are arranged such that they take over the original function of the edges of an imaginary cuboidal shape which are broken by the additional side regions (6) in the changeover from a square cross section to an octagonal cross section.
 32. The packaging as claimed in claim 18, wherein the snap-action latching connection comprises a latching element and a snap-in lug.
 33. The packaging as claimed in claim 32, wherein the latching element is provided on an inner face of the lid and the snap-in lug is provided on the associated upper edge of the inner frame.
 34. The packaging as claimed in claim 1, wherein the upper edges of the inner frame are adapted to improved closing of the lid.
 35. The packaging as claimed in claim 34, wherein the upper edges of the inner frame have a quarter-circle-like termination and a recess is thus produced at the upper end of the edges of the inner frame.
 36. The packaging as claimed in claim 1, wherein closed packaging has a vertical box compression strength of at least 500 N to 2500 N.
 37. The packaging as claimed in claim 1, wherein at least regions of the inner frame are adhesively bonded to the folding box.
 38. A folding blank for forming a powder-tight packaging for a pulverulent product, comprising: at least one rear face (2), one front face (1) and two end faces of the packaging that are attached to one another and delimited by folding lines, which folding blank, in order to construct the packaging, is closed to form a tubular shape, and wherein said folding blank further comprises at least one lid flap (8) and at least one base flap (9) for closing the base and the lid and for forming the base surface and the lid surface of the packaging, which surfaces respectively adjoin lower and upper edges of the front face (1), the rear face (2) and/or the end faces via folding lines, wherein the base surface and the lid surface of the packaging each have a quadrilateral shape, and wherein the folding blank comprises additional side regions (6) that extend-between the rear face (2) and each end face and between the front face (1) and each end face, so that the closed tubular shape has a cross section with more than four comers in its middle region, and wherein each of the additional regions (6) tapers to form points (7) at its lower and upper ends, with the lower point being involved in the formation of one of the comers of the base surface and the upper point being involved in the formation of one of the corners of the lid surface. 